Sewing machine



FIG. 1 is a front perspective view of a sewing machine showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof; and,

FIG. 6 is a rear elevational view thereof.

The broken lines shown in the drawing disclosure are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a sewing machine, as shown and described. 